When Track Changes is activated, the section will be highlighted. Deletions will appear with a strikethrough, while additions will be underlined. Modifications made by different authors will be displayed in various colors. 

When Track Changes is deactivated, the section will no longer be highlighted. Word will cease to mark changes, but the colored underlines and strikethroughs will remain visible in the document.

Tip: You can also enable a Track Changes indicator on the status bar. Simply right-click on the status bar and choose the Track Changes option.

Choose whose changes to track

You can choose to track only your own changes or everyone's changes.

To track only your own changes - Go to Review > Track Changes > Just Mine.

To track everyone's changes - Go to Review > Track Changes > For Everyone.

To prevent others from disabling Track Changes, you can set a password. Navigate to Review > Track Changes > Lock Tracking to implement this feature.
 

Decide how you prefer to view the modifications in the document. You have the option to select the type of markup you wish to display. Navigate to the Review tab and choose All Markup from the dropdown menu. You can then select one of the following options:

• Simple Markup shows tracked changes with a red line in the margin.
• All Markup presents tracked changes using various colors for text and lines, distinguishing each reviewer.
• No Markup conceals the markup, allowing you to see the document with the changes integrated. 
• Original reveals the initial document without any tracked changes or comments. 

However, any tracked changes or comments that have not been accepted, rejected, or deleted will still be present in the document.

Select the method for displaying track changes.

You have the option to determine both the types of revisions that are visible and their presentation format. If you opt to display revisions as balloons, they will appear in the document's margins. Alternatively, you can choose to show them inline, where all deletions are indicated with strikethroughs rather than in balloons.

Navigate to Review > Show Markup.

Choose Balloons and then select your preferred display option.

Display Revisions in Balloons

Display All Revisions Inline

Display Only Formatting in Balloons

Display changes by type of edit 

Go to Review > Show Markup.

Select the type of edit.

Insertions and Deletions

Formatting

The check mark next to the item indicates that it's selected.  

Access tracked changes within the Changes menu section. You can move from one tracked change to the next. In the Review tab under Changes, click on Next to see the subsequent tracked change. To view the prior tracked change, select Previous in the same section.